عنوان مجله
|
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
|
کلیدواژهها
|
composites, mechanical, metallic matrix, nonferrous
metals, powder metallurgy, sintering, static
|
چکیده
|
The presence of large grains within nanometric and ultrafine grain matrix is an effective method in order to
enhance strength while keeping the high ductility of metals. For this purpose, in this research, spark plasma
sintering (SPS) was used to consolidate milled Cu and Cu-SiC powders. In SPS process, local sparks with
high temperature between particles take place and locally lead to intense grain growth, and therefore, this
method has the ability to produce bimodal grain structures in copper and copper-based composites.
Microstructural and mechanical studies showed 185 and 437 nm matrix grain sizes, high tensile yield
strength values of 188.4 and 296.9 MPa, and fracture strain values of 15.1 and 6.7% for sintered Cu
and Cu-4 vol.% SiC nanocomposite materials, respectively. The presence of nanoparticles promoted the
occurrence of static recrystallization and decreased the fraction of coarse grains in microstructure. The
high tensile properties of the produced materials are attributed to fine grain size, homogenous dispersion of
nanoparticles and retarded grain boundary migration during sintering.
|